Sky has submitted a formal request to telecoms regulator Ofcom for a competition inquiry into BT.
The broadcasting company accuses its rival of making a series of errors in its Openreach division, which operates the national broadband network.
It says the department misses more than 500 appointments every month for installing new lines for Sky customers, and that it fails to complete a further 4,000 jobs each month.
Sky accuses BT of “failing” broadband customers and businesses, according to the Mail Online. The request will be published tomorrow.
Based on research by Frontier Economics, Sky also claims BT has not invested enough in Openreach, and that the division should therefore be split from BT – a desire shared by other competitors including TalkTalk.
Openreach's current dominance over the UK's telecoms network means all competitors are reliant upon BT for access, despite Sky having a third of all UK broadband customers signed up.
Mai Fyfield, chief strategy officer for Sky, said:
Problems in broadband are important to the economy as a whole. They affect competition and have a direct impact on consumers and small firms, resulting in dissatisfaction and loss of productivity.
She added that Ofcom should move “fast” to ask the Competition & Markets Authority to undertake a full inquiry.
It's not the first time the two companies have clashed with each other – they have also gone to court over whether Sky should have to wholesale its key sports channels to its rivals.
BT responded by saying Sky “fails to acknowledge” that Openreach has passed all 60 of Ofcom's service targets.
Sky can only substantiate its claim by ignoring the billions of pounds we have pumped into fibre broadband.